Bones and Cartilage provides the most in-depth review ever assembled on the topic. It examines the function, development and evolution of bone and cartilage as tissues, organs and skeletal systems. ...It describes how bone and cartilage is developed in embryos and are maintained in adults, how bone reappears when we break a leg, or even regenerates when a newt grows a new limb, or a lizard a tail. This book also looks at the molecules and cells that make bones and cartilages and how they differ in various parts of the body and across species. It answers such questions as "Is bone always bone?" "Do bones that develop indirectly by replacing other tissues, such as marrow, tendons or ligaments, differ from one another?" "Is fish bone the same as human bone?" "Can sharks even make bone?" and many more.* Complete coverage of every aspect of bone and cartilage * Full of interesting and unusual facts * The only book available that integrates development and evolution of the skeleton * Treats all levels from molecular to clinical, embryos to evolution * Written in a lively, accessible style * Extensively illustrated and referenced * Integrates analysis of differentiation, growth and patterning * Covers all the vertebrates as well as invertebrate cartilages * Identifies the stem cells in embryos and adults that can make skeletal tissues
Summary
Discovered in chick embryos by Wilhelm His in 1868 and named the neural crest by Arthur Milnes Marshall in 1879, the neural crest cells that arise from the neural folds have since been shown ...to differentiate into almost two dozen vertebrate cell types and to have played major roles in the evolution of such vertebrate features as bone, jaws, teeth, visceral (pharyngeal) arches, and sense organs. I discuss the discovery that ectodermal neural crest gave rise to mesenchyme and the controversy generated by that finding; the germ layer theory maintained that only mesoderm could give rise to mesenchyme. A second topic of discussion is germ layers (including the neural crest) as emergent levels of organization in animal development and evolution that facilitated major developmental and evolutionary change. The third topic is gene networks, gene co‐option, and the evolution of gene‐signaling pathways as key to developmental and evolutionary transitions associated with the origin and evolution of the neural crest and neural crest cells.
The concept of germ layers has been one of the foremost organizing principles in developmental biology, classification, systematics and evolution for 150 years (refs 1 - 3). Of the three germ layers, ...the mesoderm is found in bilaterian animals but is absent in species in the phyla Cnidaria and Ctenophora, which has been taken as evidence that the mesoderm was the final germ layer to evolve. The origin of the ectoderm and endoderm germ layers, however, remains unclear, with models supporting the antecedence of each as well as a simultaneous origin. Here we determine the temporal and spatial components of gene expression spanning embryonic development for all Caenorhabditis elegans genes and use it to determine the evolutionary ages of the germ layers. The gene expression program of the mesoderm is induced after those of the ectoderm and endoderm, thus making it the last germ layer both to evolve and to develop. Strikingly, the C. elegans endoderm and ectoderm expression programs do not co-induce; rather the endoderm activates earlier, and this is also observed in the expression of endoderm orthologues during the embryology of the frog Xenopus tropicalis, the sea anemone Nematostella vectensis and the sponge Amphimedon queenslandica. Querying the phylogenetic ages of specifically expressed genes reveals that the endoderm comprises older genes. Taken together, we propose that the endoderm program dates back to the origin of multicellularity, whereas the ectoderm originated as a secondary germ layer freed from ancestral feeding functions.
Epigenetics Hallgrímsson, Benedikt; Hall, Brian K
2011., 20110411, 2011, 2011-04-11
eBook
Illuminating the processes and patterns that link genotype to phenotype, epigenetics seeks to explain features, characters, and developmental mechanisms that can only be understood in terms of ...interactions that arise above the level of the gene. With chapters written by leading authorities, this volume offers a broad integrative survey of epigenetics. Approaching this complex subject from a variety of perspectives, it presents a broad, historically grounded view that demonstrates the utility of this approach for understanding complex biological systems in development, disease, and evolution. Chapters cover such topics as morphogenesis and organ formation, conceptual foundations, and cell differentiation, and together demonstrate that the integration of epigenetics into mainstream developmental biology is essential for answering fundamental questions about how phenotypic traits are produced.
This book is the first in a projected series on Evolutionary Cell Biology , the intent of which is to demonstrate the essential role of cellular mechanisms in transforming the genotype into the ...phenotype by transforming gene activity into evolutionary change in morphology. This book — Cells in Evolutionary Biology — evaluates the evolution of cells themselves and the role cells have been viewed to play as agents of change at other levels of biological organization. Chapters explore Darwin’s use of cells in his theory of evolution and how Weismann’s theory of the separation of germ plasm from body cells brought cells to center stage in understanding how acquired changes to cells within generations are not passed on to future generations.
Chapter 7 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 3.0 license. https://s3-us-west-2.amazonaws.com/tandfbis/rt-files/docs/Open+Access+Chapters/9781315155968_oachapter7.pdf
Buried alive: How osteoblasts become osteocytes Franz‐Odendaal, Tamara A.; Hall, Brian K.; Witten, P. Eckhard
Developmental dynamics,
January 2006, Letnik:
235, Številka:
1
Journal Article
Background and Aims
Depression and anxiety are often comorbid with alcoholism and contribute to craving and relapse. We aimed to estimate the prevalence of life‐time diagnoses of major depressive ...disorder (MDD), substance‐induced depression (SID), anxiety disorder (AnxD) and substance‐induced anxiety (SIA), the effects of these comorbidities on the propensity to drink in negative emotional states (negative craving), and test whether these effects differ by sex.
Design
Secondary analyses of baseline data collected in a single‐arm study of pharmacogenetic predictors of acamprosate response.
Setting
Academic medical center and affiliated community‐based treatment programs in the American upper mid‐west.
Participants
A total of 287 males and 156 females aged 18–80 years, meeting DSM‐IV criteria for alcohol dependence.
Measurements
The primary outcome measure was ‘propensity to drink in negative emotional situations’ (determined by the Inventory of Drug Taking Situations) and the key predictors/covariates were sex and psychiatric comorbidities, including MDD, SID, AnxD and SIA (determined by Psychiatric Research Interview of Substance and Mood Disorders).
Findings
The prevalence of the MDD, SID and AnxD was higher in females compared with males (33.1 versus 18.4%, 44.8 versus 26.4% and 42.2 versus 27.4%, respectively; P < 0.01, each), while SIA was rare (3.3%) and did not differ by sex. Increased propensity to drink in negative emotional situations was associated with comorbid MDD (β = 6.6, P = 0.013) and AnxD (β = 4.8, P = 0.042) as well as a SID × sex interaction effect (P = 0.003), indicating that the association of SID with propensity to drink in negative emotional situations differs by sex and is stronger in males (β = 7.9, P = 0.009) compared with females (β = −6.6, P = 0.091).
Conclusions
There appears to be a higher prevalence of comorbid depression and anxiety disorders as well as propensity to drink in negative emotional situations in female compared with male alcoholics. Substance‐induced depression appears to have a sex‐specific effect on the increased risk for drinking in negative emotional situations in males.
Herbs have been used for medicinal purposes, including the treatment of diabetes, for centuries. Plants containing flavonoids are used to treat diabetes in Indian medicine and the green tea ...flavonoid, epigallocatechin gallate (EGCG), is reported to have glucose-lowering effects in animals. We show here that the regulation of hepatic glucose production is decreased by EGCG. Furthermore, like insulin, EGCG increases tyrosine phosphorylation of the insulin receptor and insulin receptor substrate-1 (IRS-1), and it reduces phosphoenolpyruvate carboxykinase gene expression in a phosphoinositide 3-kinase-dependent manner. EGCG also mimics insulin by increasing phosphoinositide 3-kinase, mitogen-activated protein kinase, and p70(s6k) activity. EGCG differs from insulin, however, in that it affects several insulin-activated kinases with slower kinetics. Furthermore, EGCG regulates genes that encode gluconeogenic enzymes and protein-tyrosine phosphorylation by modulating the redox state of the cell. These results demonstrate that changes in the redox state may have beneficial effects for the treatment of diabetes and suggest a potential role for EGCG, or derivatives, as an antidiabetic agent.
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